Creative financing- Deal or No deal?

[Jay Jonez]

 Wondering how I could structure this
I have a seller who has his ear opened to do a seller finance deal/ mortgage wrap. He has a tenant that's renting the property for 3+ years for $1000/month.The seller wants $80K for the property and its ARV is $100K in a nice area that could rent for $1100-$1200 / month.
Seller is willing to take $800 and give me what ever I rent out the unit for which right now would be $200.

Monthly Payment (PITI)- $700

Interest rate : unknown at the moment but could be 3.5 

Loan type: Conventional 

How could would you work this deal if you did creative financing?